add net grpc

cmd/sshpiperd/grpc.go

@@ -0,0 +1,102 @@
+package main
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"fmt"
+	"io/ioutil"
+
+	"github.com/tg123/sshpiper/cmd/sshpiperd/internal/plugin"
+	"github.com/urfave/cli/v2"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials"
+	"google.golang.org/grpc/credentials/insecure"
+)
+
+func createNetGrpcPlugin(args []string) (grpcPlugin *plugin.GrpcPlugin, err error) {
+	app := &cli.App{
+		Name:            "grpc",
+		Usage:           "sshpiperd grpc plugin",
+		HideHelpCommand: true,
+		HideHelp:        true,
+		Flags: []cli.Flag{
+			&cli.StringFlag{
+				Name:     "endpoint",
+				Usage:    "grpc endpoint address",
+				EnvVars:  []string{"SSHPIPERD_GRPC_ENDPOINT"},
+				Required: true,
+			},
+			&cli.BoolFlag{
+				Name:    "insecure",
+				Usage:   "disable tls",
+				EnvVars: []string{"SSHPIPERD_GRPC_INSECURE"},
+			},
+			&cli.StringFlag{
+				Name:    "key",
+				Usage:   "grpc client key path",
+				EnvVars: []string{"SSHPIPERD_GRPC_KEY"},
+			},
+			&cli.StringFlag{
+				Name:    "cert",
+				Usage:   "grpc client cert path",
+				EnvVars: []string{"SSHPIPERD_GRPC_CERT"},
+			},
+			&cli.StringFlag{
+				Name:    "cacert",
+				Usage:   "grpc ca cert path",
+				EnvVars: []string{"SSHPIPERD_GRPC_CACERT"},
+			},
+		},
+		Action: func(c *cli.Context) error {
+
+			var secopt grpc.DialOption
+			if c.Bool("insecure") {
+				secopt = grpc.WithTransportCredentials(insecure.NewCredentials())
+			} else {
+
+				clientCert, err := tls.LoadX509KeyPair(c.String("cert"), c.String("key"))
+				if err != nil {
+					return err
+				}
+
+				config := &tls.Config{
+					Certificates: []tls.Certificate{clientCert},
+				}
+
+				cacert := c.String("cacert")
+				if cacert != "" {
+					ca, err := ioutil.ReadFile(cacert)
+					if err != nil {
+						return err
+					}
+					certPool := x509.NewCertPool()
+					if !certPool.AppendCertsFromPEM(ca) {
+						return fmt.Errorf("failed to append ca")
+					}
+
+					config.RootCAs = certPool
+				}
+
+				secopt = grpc.WithTransportCredentials(credentials.NewTLS(config))
+			}
+
+			conn, err := grpc.Dial(c.String("endpoint"), secopt, grpc.WithBlock())
+			if err != nil {
+				return err
+			}
+
+			grpcPlugin, err = plugin.DialGrpc(conn)
+			if err != nil {
+				return err
+			}
+
+			return nil
+		},
+	}
+
+	if err := app.Run(args); err != nil {
+		return nil, err
+	}
+
+	return grpcPlugin, nil
+}